Multiple-fuse plug



Patented June 24, 1930 ROBERT T. SMITH, OF KANSAS CITY, MISSOURIMULTIPLE-FUSE PLUG Application filed August 19, 1929. Serial No.386,924.

The present invention relates to fuse plug devices, and the primaryobject in view is to devise an improved multiple fuse construction forsuch plug appliances, adapted 6 to render the appliance operative for agiven number of times, depending upon the number of fuse elementsembodied therein and adapted to be brought into operative positionsuccessively by the simple rotation 10 of the movable part carrying thefuse ele-' ments, and thereby tric circuit.

It is also sought to provide a neat, simple and compact, as well assightly construction,

15 adapted to be quickly operated, and also -having means for visuallyindicating the number of fuse elements and the successive order in whichthey are brought into use.

With the foregoing general object in 20 view, the invention will now bedescribed by reference to the accompanying drawing illustrating one formof construction which I have devised for embodying the proposedimprovements, after which those features and combinations deemed to benovel will be set forth and claimed.

In the drawing-- Figure 1 is a side view, illustrating a multiple fuseplug constructed in accordance with my invention;

Figure. 2 is a central tional view;

Figure 3 is an enlarged sectional detail of the fuse-containing andadjusting parts of the device;

Figure 4 is an interior view shown in Figure 3; and' Figure 5 is a faceview of the outer end of the plug.

again restoring the eleclongitudinal secof the parts '40 Referring tothe drawing in detail, this illustrates the improved device ascomprising a hollow body or plug portion proper 8 adapted to beconstructed of bakelite, porcelain or other suitable non-conducting material, having the exteriorcontact element 10 constituting one of theterminals of the plug, from. which a pin or post 11 pro ects upcentrally into the hollow interior chamber 12 of the plug. Surroundingthe plug 50 is the usual metallic shell 14 adapted to fit the fuseplug-receiving socket and constituting the other terminal-of the plug,and also having an extension projecting through the side wall of theplug and terminating in a lip or brush element 15 overhanging an interior annular shoulder 16 formed around the chamber 12 as illustratedin Figure 2.

The multiple fuse structure comprises a disk 18 of non-conductingmaterial carrying the fuse elements which are formed with the centraldisk portion 19 having a plurality of radiating arms 20 (having thereduced neck portions 20') extending across one face of the disk 18,over its margin, and thence inwardly partly over the opposite face ofsaid disk 18. 'An insulating washer 22 is fitted over the hub portion 21of the disk 18 into retaining engagement with the terminations of thearms 20, as shown in Figure 3, while at the opposite face of the disk 18the material thereof projects sufficiently past the exposed surfaces ofsaid arms 20 to form ribs 24, and hence depressions between said ribs,for a purpose hereinafter explained.

The disks 18-19 are provided with a central opening 25 for mounting thesame 2 upon the inner end of 26 having the external button 27, theenlarged shank portion 28 of said screw being journaled in an opening 29in the cap piece or shell, 30 fitting over the hollow end of the plug.body 8 and having its side or cylindrical portion formed with detents 32engaging corresponding recesses cut in the sides of said body, asillustrated in Figures 1 and 2.

' A coil spring 35 is mounted around the screw 26 between the cap pieceand the washer 22; a second insulating washer 36 is mounted on the andthe cap piece, and both washers are formed with central bosses forcentering the spring with'reference to the screw.

Upon the inner end of the screw 26 is se- ('ulQd, by means of a nut 38,a spring jack element comprising the intermediate porlion 39 engagingthe screw and the spring arms 40 formed with the inturned overlap pingand perforated terminals 41 for wipan operating screw screw between thespring ing engagement with the post 11, as shown in Figure 2. The nutincidentally serves to secure the fuse disks upon the screw 26 with thehub portion 21 of the disk 18 in abutting engagement with the shankportion 28 of the screw, said shank portion preferably terminating in asquared formation for insuring positive turning movement pf the disks inthe operation of the device.

With the parts assembled as shown in Fig ure 2, the function of thespring is such as to actuate the fuse member yieldingly in the directionof the shoulder 16, and, as the fuse structure is turned, by means ofthe button 27, bringing the arms 20 of the fuse elements successivelyopposite the contact lip or brush element 15, these arms aresuccessively actuated into contact engagement with said lip 15. Thedepressions formed around these arms by the ribs 24 serve to latch thefuse structure in these successive positions, necessitating a slightretraction of the button and screw for unlatching the fuse member fromengagement with the lip, preliminarily to each turning movement, as willbe readily understood. The sliding contact between the arms 40 of thejack element and the pin 11 accommodates this retracting movement of thefuse structure.

Preferably, suitable vent openings 7 are provided in the sides of theplug for escape of gases from the interior whenever a fuse is blown,

It will thus be apparent that I have devised, a simple, practical andefficient multiple fuse plug structure adapted to fulfill the desiredobjects of the invention, and

while I have illustrated the preferred form of construction, I desire toreserve the right to make such changes as may fairly fall within thescope of the following claims.

Having thus described my invention, what I claim and desire to secure byLetters Patcut is:

1. A multiple fuse structure comprising a hollow plug element containinga pin terminal and an interior brush terminal, a cap piece fitting theopen end of said plug, a rotary disk journaled in said cap )iece andcarrying a spring jack yoke sliding y engaging said pin terminal, aplurality of radial fuse elements carried by said disk forselectiveengagement with said brush element, said disk being formedwith ribsseparating said fuse arms and providing radial depressions between saidribs, and means permit-- ting slight retracting movement of said diskfor seating and unseatmg said brush element in said depressions.

2. A multiple fuse structure comprising a hollow plug element containinga. pin terminal and an interior brush terminal, a cap piece fitting theopen end of said plug, a 1'0- tary and axially movable pin carried bysaid cap piece, .a disk carried by said pin and signature.

ROBERT T. SMITH.

